they dont sound like they're really your friends... you should hang out with people that wont pressure you to come out with them and wont leave you out.
maybe you should try to tell them how you feel? I mean ranting is good but you're not going to get anywhere if they dont know what's up.
They probably dont leave you out on purpose, so try to see it from their point of view.
If you really cant handle being around them try making new friends that you'll feel more comfortable around
